Refrigerant evaporator



EP 1 L. w. ATCHISON REFRIGERANI' EVAPORATOR l-Filed Sept. 7, 1940 Inventor- Leonard W Atchison by W 6? JMMH His Att orhey.

Patented Sept. 30, 194i UNl'lED ST A-T-ES PATENT OFFICE 2.251441- -m W-htchiaon, Schenectady, 1v. 1., uaignot to. General Electric Company, a corporation of New York Application September 1, 1940, Serial No. 355,753

My invention relates to evaporators for refrigerating machines and particularly to refrigerant evaporators of the non-floodedtype.

In the operation of refrigerantevaporators of the non-flooded type, difficulty is sometimes encountered because of the sluggin back of liquid refrigerant through the suction line' to the compressor. The admission of liquid refrigerant Another object of my invention is to provide an evaporator conduit having an improved arrangement for checking the flow therethrough of slugs of liquid refrigerant.

Further objects and advantages of my invention will become apparent as the following description proceeds and features of novelty which characterize my invention will be pointed out I with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention,

reference may be had' to the accompanying draw- 'ing in whichFig. 1 is a sectional front elevation view of a household refrigerator'provided with an evaporator embodying my invention, and Fig. 2 is an enlarged sectional view on the line 2-2 of Fig. 1. l 1

The evaporator shown in the accompanying drawing comprises a sheet metal structure provided with a sinuous indentation forming a refrigerant conduit extending from an inlet near the bottom of the evaporator to an outlet near of liquid refrigerant tend to flow into the pockets] due to their momentum while the gaseous refrigerant flows on through the conduit. The liquid refrigerant willthen flow back into the conduit by gravity after the initial surge has thus been checked.

Referring no f to the drawing in Fig. 1, 1 have fslugs of liquid to the suction line.

8 Claims. (01. 62126) shown a householdrefrigerator comprising a cabinet ll having a food storage compartment Ii surrounded by thermally insulated walls i2, ac-

cess to the compartment being had through a suitable door (not shown) provided in the front of thecabinet. A compartment i3 is provided in the lower portion of the cabinet and contains a refrigerant condensing unit comprising a hermetically sealed casing ll containing a motor driven refrigerant compressor arranged to supply compressed refrigerant through a discharge line It to a condenser ii. The condenser l6 and the casing it are cooled by operation of a fan il driven by a motor ll secured to the casing it. Air for cooling the casing and the condenser is admitted to the compartment I! through an opening provided with louvers i9 and is discharged therefrom through an opening provided with louvers 20. The compressed refrigerant in the condenser I is cooled and liquefied and flows to a liquid receiver or float valve chamber 2i. When a predetermined amount of liquid refrigerant has collected in the receiver 2|, a. float therein rises to open a valve, and they refrigerant is then discharged through a liquid line 22 and flows upwardly to asinuou's conduit 23 of substantially uniform cross section throughout its lengthand formed in a sheet metal evaporator 24 arranged within the compartment ll.- Liquid refrigerant in the evaporator 24 is vaporized by 'the absorption of heat from the air within compartment II and the vaporized refrigerant is'withdrawn from the evaporator'through a suction line 25 by operation of the compressor within thecasing i4. During normal operation of the evaporator, liquid refrigerant is admitted to the lower end of the conduit and flows upwardly through the conduit assisted by gaseous refrigerant vaporized from the liquid. At times, particularly when the float valve is first opened, there may, be a rush or surge of liquid refrigerant throughthe conduit; this ,tends to discharge In order to prevent slugs of liquid refrigerant from reaching the outlet of the evaporator, I have provided a plurality of chambers or pockets 26 arranged in communication with the conduit 23 at the return bends which connect the several horizontal runs of the conduit. The chambers 26 .are connected to the. bends by short passages 21 extending tangentially of the respective return bends vwith which-they. are connected so that chambers 26 The arrangement of the chambers 26 therefore checks any sudden surge of slugs of liquid refrigerant through the evaporator. Since the chambers 26 are arranged above the portions of the conduit 23 to which they are connected, the liquid refrigerant which. enters' the chambers 26 flows back intothe conduit where it is vaporized in the usual manner.

The construction of the chambers 26 is more clearly shown in Fig. 2 in which the evaporator is shown as constructed of two metal sheets 28 and 29. The'sheet29 has been: illustrated as a portion of the metal inner liner of the compartment II. The sheet 28 is provided with suitable indentations forming the sinuous conduit 23 andalso the chambers 26 and their passages 21, and

the two sheets are welded or otherwise suitably secured together around the edge-of the sheet 28 and between the indentations to make the evaporator pressure-tight. I prefer to form the chambers 26 near the curved end portions or return bends'of the conduit 23 in order to make use of. the momentum of the liquid refrigerant to separate the liquid fromthe stream of gaseous refrigerant flowing through the evaporator. It will be readily understood that, although the slugs of liquid are thrown into the chambers 26, the gaseous refrigerant continues in its passage through the conduit 23.

It will be apparent from the foregoing that I have provided an eflective and easily constructed arrangement-for preventing slugging back or the discharge of liquid refrigerant from an evap orator which maintains a high operating em- I ciency of the system and minimizes the danger Letters Patent of the United Statesis:

1. A refrigerant evaporator comprising a conduit having an inlet and an outlet, said conduit having a substantially uniform cross section throughout its length, means providing a. chamber in direct communication with an intermediate portion of said conduit, said chamber being arranged in line with the direction of refrigerant flow in said portion of said conduit whereby any slugs of liquid refrigerant flowing through said portion of said conduit will tend to be thrown by their momentum from said conduit into said chamber.

2. A refrigerant evaporator comprising a conduit having a curved portion and having an inlet and an outlet, aid conduit having a substantially uniform cross section throughout its length,

means providing a-ohamber in directcommunication with said curved portion of said conduit, said chamber being arranged in a tangential line with respect to said curved portion of said conduit whereby any slugs of liquid refrigerant flowing through said curved portion will tend to be thrown by their momentum from said conduit into said chamber.

'3. A refrigerant evaporator comprising a conduit havingan inlet and an outlet, said conduit having a substantially uniform. cross section throughout its length, means providing a chamber above an intermediatejportion of said con duit and in direct communication therewith, said chamber being arranged in line with the direction of refrigerant flow in said portion of said conduit whereby any slugs of liquid refrigerant flowing through,said' portion will tend to be thrown by their momentum from said conduit upwardly into said chamber.

4. A refrigerant evaporator comprising a sinuous conduit having a plurality of turns and having an inlet and an outlet, said conduit having through said turns will tend-to be thrown by their momentum from each of said turns into the respective one of said chambers communicating therewith. i

5. A refrigerant evaporator comprising a sinuous conduit providing a plurality of horizontal runs connected by return bends and arranged in an upwardly extending plane, said conduit having an inlet near the bottom thereof and an outlet near the top thereof, means providing chambers in direct communication with said conduit at a plurality of said bends, eachof said chambers being arranged above and in direct communication with its respective one of said bends in a line tangential to the direction of flow of refrigerant in said respective bend whereby any slugs of liquid refrigerant flowing through said bends will tend to be thrown by their momentum from said bends into the respective chambers in communication therewith, the liquid refrigerant thrown into said chambers thereafter flowing by gravity back to said conduit.

6. A refrigerant evaporator comprising-a conduit having an inlet and an outlet and an intermediate curved portion,said conduit having a substantiallyuniform cross section throughout its length, means providing a chamber anda direct connection between said chamber and said curved portion of said conduit, the direct connection between said chamber and said conduit being in a tangential line with respect to said curved portion of said conduit whereby any slugs of liquid refrigerant flowing through said curved portion will tend to be thrown by their momentum from said conduit into said chamber.

7. A refrigerant evaporator comprising two sheet metal portions secured together'in fac engagement, at least one of said portions having an indentation therein forming a refrigerant conduit between said sheet metal portions, said conduit having an inlet and an outlet and an intermediate curved portion, said conduit having a substantially uniform cross section throughout its length, and an indentation formed in at least one of said sheet metal portions for providing a chamber in direct communication with said curved portion of said conduit, the entrance from said chamber to said curved portion being on a line tangential to the direction of flow of refrigerantthrough said curved portion whereby any slugs of liquid refrigerant flowing through said curved portion will tend to be thrown by their momentum from said conduit into said chamber.

8. A refrigerant evaporator comprising an upwardly extending sheet metal wall having a sinumenu A '3 ans eondmt comprisin: a plurality of horizontalrunseonnectedbyrewrnbendsandhavin:

an inlet near the lower end thereof and an outlet near the upper end thereof. means provid-" in: chambers in direct eommimication with said conduit at a plurality of said bends. each of said chambers be'in: arranged above and in direct eommnnieationwithitarespectlvebendinallne tangential to the direction oliiow of refrigerant in said resnective bend whereby any slugs of liquid refrigerant flowing through said bends will tend to be thrown by their momentum from said.

bends into'tbe respectivechambers in communieation therewith, the liquid refrlaerantthrown into said chambers thereafter nowinc y g avity back to said conduit.

momma w. 'rcmsorz; 

